Warp knit elastic fabrics are commonly used as belting for undergarments and the like. The fabric in the form of a strip is sewn along a bottom edge to the waist portion of the undergarment and sewn at its ends to form a butt type joint. If through production errors the joint is uneven, a portion of the end of the fabric will extend above the joint. A problem with conventional warp knit elastic fabrics is a tendency of this upstanding end portion to unravel along a lateral edge which forms the upper edge of the waistband.
One form of prior art elastic warp knit fabric which has attempted to overcome this unraveling tendency has utilized a plurality of base yarns each knitted in closed loops in successive courses which are joined by filler yarns extending in a weft direction and which are contained in the closed loops. A so-called locking yarn is knitted into each course of the two warps adjacent a lateral edge of the fabric such that an open loop is formed in each course but in alternate wales. It has been found however that such fabric may still unravel under certain conditions such as described previously where the fabric is utilized as a belting and the butt joint between the ends of the fabric is uneven.
It is therefore an object of my invention to provide for an elastic warp knit fabric which may be utilized as belting for undergarments and the like which will have a structure to resist unraveling even in the event that in the manufacture of the garment the ends of the fabric forming the belting are misjoined with an exposed portion extending over one lateral edge.
Broadly my invention comprises having an elastic warp knit fabric made up of a plurality of base yarns with each base yarn knitted in successive courses to form a plurality of successive closed loops which extend in a warp direction and which form a plurality of individual wales. At least one of the wales comprises a locking wale and at least one of the wales an intermediate wale. An elastic yarn is laid into at least one intermediate wale and at least one locking wale. A first filler yarn extends in a weft direction in each course and is contained within the closed loops of adjacent wales to connect the wales together in a weft direction. A locking yarn is knitted into a locking wale in open loops in alternate courses of the wale and has a portion extending in a weft direction along with the filler yarn such that it is contained in the closed loops of at least one intermediate wale. Preferably the locking wale forms one lateral edge of the fabric and includes also an adjacent locking wale followed by a plurality of intermediate wales. The locking yarn has a weft extending portion which extends preferably over a plurality of intermediate wales. A second filler yarn may be included and preferably extends parallel to the initial filler yarn.